Script to change git commits' author

git-change-author.sh

#!/bin/sh

# Usage message if number of arguments are invalid.
if [ "$#" -ne 3 ] ; then
	echo "usage: sh $0 wrong-email new-email new-name"
	exit 1
fi

# Save args to variables.
WRONG_EMAIL="$1"
NEW_EMAIL="$2"
NEW_NAME="$3"

# Use a git filter-branch to batch script to fix your username and email values
# in one or multiple commits, within the branches.
# Source: https://www.git-tower.com/learn/git/faq/change-author-name-email
git filter-branch --env-filter '
  WRONG_EMAIL='\'$WRONG_EMAIL\''
  NEW_EMAIL='\'$NEW_EMAIL\''
  NEW_NAME='\'$NEW_NAME\''
  
  if [ "$GIT_COMMITTER_EMAIL" = "$WRONG_EMAIL" ]
  then
      export GIT_COMMITTER_NAME="$NEW_NAME"
      export GIT_COMMITTER_EMAIL="$NEW_EMAIL"
  fi
  if [ "$GIT_AUTHOR_EMAIL" = "$WRONG_EMAIL" ]
  then
      export GIT_AUTHOR_NAME="$NEW_NAME"
      export GIT_AUTHOR_EMAIL="$NEW_EMAIL"
  fi
' --tag-name-filter cat -- --branches --tags